1. Field of the Invention
The invention relates to a liquid crystal panel and, in particular, to a reflective or transflective liquid crystal panel with a uniform background color.
2. Description of Related Art
Because of rapid developments in the semiconductor technology, semiconductor products are widely used in daily life. For example, liquid crystal display (LCD) is very common in all kinds of electronic products such as liquid crystal televisions, computer displays, hand-held game players, mobile phones and audio/video (A/V) equipment. The early active LCD uses a backlight module to be light source. The brightness of pixels of the LCD is completely determined by the strength of the backlight source. Later on, reflective type LCD and transflective type LCD are developed. The reflective type LCD uses a reflecting layer to reflect light from external environment emitting into the liquid crystal panel. However, the reflective type LCD must rely on sufficient environment light to produce clear images. To overcome this problem, the transflective LCD is invented. The light source of the transflective LCD for generating images can come from either the external environment or a backlight module.
In the aspect of display screen, both the reflective and transflective LCD's have a so-called active area (A/A) and viewing area (V/A). With reference to FIG. 8, the A/A refers to a region that can actually generate images and is located in a central part of the entire display screen and occupies a larger area. The V/A refers to a region that does not really produce images and surrounds the A/A. In the aspect of the structure, the A/A and the V/A are very similar to each other. With reference to FIG. 9, a partial cross-sectional view of a transflective liquid crystal panel is shown. The transflective liquid crystal panel includes a first substrate (71) and a second substrate (72) that are disposed opposite to each other, and separated to form an appropriate gap filled with liquid crystal (not shown).
A top surface of the first substrate (71) is formed with a reflective layer (73) made of metal material. The reflective layer (73) has an opening (730) at each pixel unit in the A/A. The lights from the backlight can pass through the openings (730). The pixel unit is a basic component of a pixel. Normally, each pixel consists of three pixel units (R, G, and B).
An inner surface of the second substrate (72) facing the first substrate (71) is formed with a black matrix (BM) (74) and a color filter (C/F) layer (75). The C/F layer (75) has different colors (red, green, and blue) for different pixel units (R, G, and B), respectively. The BM (74) within the A/A is just formed among adjacent colors of the C/F layer (75). The BM (74) within the V/A totally covers the C/F layer (75) in that region.
In accord with the above description, the difference between the V/A and the A/A of the liquid crystal panel can be understood. Even though the V/A and the A/A do not differ much in structure, there are some problems when the liquid crystal panel is used in products. With reference to FIG. 10, a liquid crystal product has a housing (80). One surface of the housing (80) has a display window (81) in which a liquid crystal panel is mounted. If the display window (81) is larger than the A/A of the liquid crystal panel, partial V/A surrounding the A/A can be seen. According to the foregoing description of FIG. 8, the A/A and the V/A have different reflective properties for external light, i.e. the V/A does not reflect external light at all. Therefore, when the liquid crystal panel is not active, the A/A and the V/A have distinct background colors that results in an unpleasant visual effect for consumers